<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            width: 200px;
            height: 200px;
            border: 3px solid #000;
            font-size: 30px;
            margin-top: 10px;
        }

        .pink {
            background-color: pink;
        }

        .big {
            width: 300px;
            height: 300px;
        }
    </style>
</head>
<body>

<div id="app">
    <!-- v-bind 切换类名 -->
    <div class="box" :class="{pink:false,big:true}">黑马程序员</div>
    <div class="box" :class="['pink']">黑马程序员</div>
</div>
<script src="./vue.js"></script>
<script>
    const app = new Vue({
        el: '#app',
        data: {}
    })
</script>
</body>
</html>